DtsPipelineComponentAttribute.SupportsBackPressure Property

Reference

Definition

Namespace:: Microsoft.SqlServer.Dts.Pipeline

Assembly:: Microsoft.SqlServer.PipelineHost.dll

Important

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Identifies the component as one that supports more than one input, and implements the optional methods for handling excessive memory usage if the inputs produce data at uneven rates.

public:
 property bool SupportsBackPressure { bool get(); void set(bool value); };

public bool SupportsBackPressure { get; set; }

member this.SupportsBackPressure : bool with get, set

Public Property SupportsBackPressure As Boolean

Property Value

Boolean

true if the component supports more than one input and implements the optional methods for handling excessive memory usage if the inputs produce data at uneven rates; otherwise, false.

Examples

In the following example, the implementation of the DtsPipelineComponentAttribute class sets the value of the SupportsBackPressure property to true.

[DtsPipelineComponent(ComponentType = ComponentType.Transform,  
        DisplayName = "Shuffler",  
        Description = "Shuffle the rows from input.",  
        SupportsBackPressure = true,  
        LocalizationType = typeof(Localized),  
        IconResource = "Microsoft.Samples.SqlServer.Dts.MIBPComponent.ico")  
]  
public class Shuffler : Microsoft.SqlServer.Dts.Pipeline.PipelineComponent  
        {  
          ...  
        }

Remarks

The first step in implementing better memory management for a custom data flow component that supports multiple inputs is to set the value of the SupportsBackPressure property to true in the T:Microsoft.SqlServer.Dts.Pipeline.DtsPipelineComponentAttribute. When the value of SupportsBackPressure is true, the data flow engine calls the Microsoft.SqlServer.Dts.Pipeline.PipelineComponent.IsInputReady method and, when there are more than two inputs, the Microsoft.SqlServer.Dts.Pipeline.PipelineComponent.GetDependentInputs method at run time.

For more information about the handling of excessive memory usage if the inputs of a custom data flow component produce data at uneven rates, see Developing Data Flow Components with Multiple Inputs.

Applies to

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